Beer in the keg, as well as other gassed products, will contain a substantial amount of gas, such as carbon dioxide, dissolved in the liquid; this liquid is kept under pressure, for two main reasons: in order to enable withdrawal from the keg; and to keep the carbon dioxide from escaping or outgassing upon such withdrawal, leaving the liquid "flat".
When carbonated beverages are handled commercially, in taverns or restaurants, pressure for dispensing and pressurizing is supplied through pressure-regulated tanks of gas, a system whose complexity and size do not make it useful or economical for home dispensing.
Systems for home storage and dispensing of larger quantities of beverage than convenient through bottles or cans have been suggested in the past, including some which keep the pressurizing medium separated from the beverage so as not to contaminate or spoil it.
One such approach may be considered as a structure which encompases the beverage container, the pressurizing means, and the pressurizing medium, all in one inseparable, cumbersome unit. The following classifies variations within the type just described. An early patent to Byrne, U.S. Pat. No. 50,085 of 1865, suggests the basic use of a bag-within-a-box, in which the beverage bag is pressurized by the weight of a sliding lid. Douglas U.S. Pat. No. 3,057,517 (1962) fixes his flexible beverage bag in the container and then pressurizes it with contained water. The later U.S. Pat. No. 3,294,289 to Bayne (1966), suggests the use of two flexible bags fixed within a single container, one pressurized with air to act on the exterior of a beverage bag or, alternatively, within the beverage bag. The latter approach was preceded by the Fleming U.S. Pat. No. 78,447 (1868) in which the pressurizing bag is in the beverage, which is itself in direct contact with the container.
Since the home-dispensing units are to be adjuncts to the home-refrigerator, they must be scaled in size and weight for ease of handling, and should easily accommodate bulk-beer in its handiest form, i.e., in refillable or disposable containers. Thus, the above-mentioned beverage bags, sealed to their various containers and thus tied to pressure reservoirs and pressurizing means, comprise cumbersome, unitary devices which could hardly be accommodated in the home-refrigerator, and in which beverage container replacement would be time- and effort-consuming.
Accordingly, it is an object of the present invention to provide a beverage storage- and dispensing-system for home-refrigerator use, wherein the beverage container may be continuously pressurized by a base-unit for dispensing and to prevent `outgassing` during use, yet is easily replaceable without disturbing the installation of the basic system. This is accomplished without compressed gases, pressure regulators, or high pressures.